Elevator seats



May 10, 1966 E. J. GAFFNEY 3,250,569

ELEVATOR SEATS Filed May 25, 1964 3 Sheets-Sheet 1 INVENTOR. Ea waeo J Gea /wry BY W, w-Fm ATTOMEY! May 10, 1966 E. J. GAFFNEY 3,250,5

ELEVATOR SEATS Filed May 25, 1964 5 Sheets-Sheet 2 4 7 45 INVENTOR.

United States Patent 3,250,569 ELEVATOR SEATS Edward J. Gatfney, 414 W. Moreland Blvd., Waukesha, Wis. Filed May 25, 1964, Ser. No. 369,960 12 Claims. (Cl. 297-330) This invention relates to 'improvements in elevator seats and particularly to a compact elevator seat unit having a low profile and adapted to be disposed between a seat cushion and seat base of a chair.

The lifting mechanism of the elevator seat unit of the present invention is compactly contained between the base and seat panels of the unit sothat nothing projects outwardly from the unit. The unit is universally adapted to fit onto the seat base of any chair and beneath its cushion, thus to convert a conventional chair to an elevator chair. No part of the elevator seat unit of the present invention need be built into the chair. When closed, the unit of the present invention is only 2% inches high. Accordingly, the seat level is raised only by 2% inches when the unit is added to a chair. The unit is portable and may be shifted from one chair to another.

Moreover, the elevator seat unit of the present invention incorporates novel elevator mechanism, including a cam and cam follower and non-parallelogram linkages by which, the seat cushion is lifted at a uniform rate and concurrently tilted forward to assist a person in arising from the seat.

The cam, cam actuating carrienand linkages are so constructed that the motor delivers substantially uniform power throughout the range of seat movement.

In one embodiment of the invention, a chair may be provided with a centering well or socket to receive the base panel of the unit.

Other objects, features and advantages of the invention will appear from the following disclosure, in which:

FIGURE 1 is a perspective view of an elevator seat unit embodying the present invention, the seat panel being shown in elevated and tilted position.

FIGURE 2 is a perspective view on a reduced scale showing the elevator unit provided with a seat cushion and with an elasticized fabric web enclosing the space between the seat-panel and base panel.

FIGURE 3 is .an enlarged fragmentary cross section taken along the line 3-3 of FIGURE 2.

FIGURE 4 is a perspective view of the elevator seat unit showing its use on a chair.

FIGURE 5 is a vertical cross section taken through an elevator seat unit embodying the present invention, the seat panel being shown in its uppermost position.

FIGURE 6 is a view partly in side elevation and partly in section through an elevator seat unit embodying the invention, the seat panel being shown in its lowermost position.

FIGURE 7 is a perspective view on a reduced scale showing the unit in its FIGURE 6 position.

FIGURE 8 is a view partly in side elevation and partly in vertical cross section taken through an elevator seat unit embodying the invention, the seat panel being shown in an intermediate position.

FIGURE 9 is a horizontal cross section taken along the line 99 of FIGURE 5.

FIGURE 10 is a fragmentary cross section taken along the line 10-10 of FIGURE 9. I

FIGURE 11 is a simplified wiring diagram for the motor of the elevator seat unit of the present invention.

FIGURE 12 is a fragmentary view, partly in elevation and partly in section, showing a chair construction especially adapted for use with an elevator seat unit of the present invention, the seat cushion in this view resting directly upon the chair bottom.

FIGURE 13 is a view partly in elevation and partly in vertical section through a chair similar to that shown in FIGURE 12, but showing the elevator seat unit interposed between the chair bottom and the seat cushion.

FIGURE 14 is an'exploded plan view of the chair of FIGURE 13 showing at the lefthand side of this view the chair of FIGURE 13 with the elevator seat unit mounted thereon, the right hand side of this view being an inverted plan view of the undersurface of the seat panel of the elevator seat unit.

Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.

One embodiment of the elevator seat unit of the present invention as shown in the drawings comprises a base panel 20 and a seat panel 21, these being respectively provided with reinforcing edge flanges 22, 23, 24, 19. The undersurface of the seat panel 21 is further provided with longitudinally extending reinforcing angles 25. The top surface of the seat panel 21 and .bottom surface of the base panel 20 are fiat or planiform. The two panels 20, 21 are interconnected by an elevator mechanism including a pair of laterally spaced adjustable channel shaped links 26 and a pair of curved links 27 which also .function as a cam by which the motor 28 raises and lowers the seat panel 21. While the base panel 20 and seat panel 21 shown in the drawing to exemplify the invention have continuous sheet surfaces, these panels could also be skeletonized or constitute grids or like air pervious frames.

The links 26 will be referred to as the forward links inasmuch as there are nearest the front of the chair, and the curved links 27 will be referred to as the rear links as they are nearest the rear of the chair when the elevator seat unit is positioned thereon as shown in FIGURES 4 and 13.

The upper ends of the front links 26 are adjustably and pivotally connected to seat panel 21 on removable pins 31 journaled on respective legs 32 of mounting brackets 30. The bracket legs 32 are each desirably provided with two sets of laterally aligned spaced holes 33, 34 which selectively receive the pin 31. The opposite ends of the links 26 are similarly adjustably mounted on pins 35 selectively receivable through sets of spaced holes 36, 37 respectively in flange 22 of the base panel 20 and a laterally'spaced bracket 38 mounted on the base panel .20, as best shown in FIGURES 1, 9 and 10. The position of the pins 31, 35 may be changed to change the degree of seat panel tilt and elevation of the front edge of the seat panel 21.

walls 44 of the cam carrier support channel 39 which is mounted on the base panel 20, and in bearing blocks 38 fastened thereto.

As best shown in FIGURE 5, the pins 31,40 connecting the top ends of the links 26, 27 to the seat panel 21 are more narrowly spaced than the, pins 35, 42 which connect the lower ends of the links 26, 27 to the base panel 20. Accordingly, the links 26, 27 comprise movable portions of a non-parallelogram linkage system connecting the seat panel 21 with the base panel 20. When the seat panel is elevated from its lowermost position shown in FIGURE 6 through its intermediate position shown in FIGURE 8 to its uppermost position in FIGURE 5, the non-parallelogram linkage aforesaid will cause the seat panel to tilt forwardly in the course of its elevation. This on the end of a screw shaft 53. The respective belts and pulleys may have cog surfaces for positive drive therebetween. Any speed reducing mechanism could be substituted for the one herein illustrated.

The screw shaft 53 is rotatably supported at the rear of the base panel 20 on an axial thrust bearing 54 and near the front end of the base panel on bearing 55. Its axis of rotation is mid way between the side walls 44 of the cam carrier support channel 39. Channel 39 extends lon gitudinally of the base panel and is provided with a bottom web 56 welded to the base panel 20. The channel 39 has elevated shoulders 57 between web 56 and sides 44 to form tracks for the roller wheels 58 of a carriage or drawblock 61 which is in threaded connection with the shaft 53.

There is another set of roller wheels 62 on the respective shaft portions 63 of the drawblock 61 and which turn independently of the roller wheels 58. Roller wheels 62 are aligned with the curved link arms 27, as best shown in FIGURE 10. Accordingly, when shaft 53 is turned 'by motor 28, the drawblock or carriage 61 will be moved axially of the shaft 53. Outermost roller Wheels 53 will roll on the tracks 57 and the innermost pair of roller wheels 62 will exert a camming effect upon the links 27 to raise or lower the seat panel 21 and will support the weight of a person sitting on the seat.

The undersurfaces 64 of links 27 are curved so that the angle of incidence of the cam links 27 with their rollers 62 will change throughout the range of movement of the roller carriage 61 along its tracks 57. The construction is such that throughout the range of movement of the seat panel 21, as illustrated in FIGURES 6, 8 and 5, the load on the motor 28 will be substantially constant and the seat panel 21 will have a substantially constant rate of change in position.

FIGURE 6 shows the lowermost position of the seat panel 21. At this point, the carriage 61 is farthest from the pivot pin 42 about which the cam link 27 turns. Accordingly, horizontal movement of carriage 61 will not tend to lift the link 27 as much as it would tend to do so near the end of rearward horizontal movement of the carriage when it is close to the pin 42, as shown in FIG- URE 5, and has high mechanical advantages with respect thereto. However, because of the curved undersurface 64 of the cam link 27, cam link 27 will have a much greater angle of incidence with the carriage Wheel 62 in its FIGURE 6 position than it will in its FIGURE position, where mechanical advantage is low. Accordingly,

the changing angle of incidence of the curve of the cam surface 64 will compensate for the changing mechanical advantage of the roller as it moves with respect to the pivot pin 42, thus to give a uniform rate of rise of the seat panel 21 regardless of the specific position of the carriage 61.

The motor 28 is controlled by the electrical circuit shown in FIGURE 11. There is a control box 65 having an up button 66 and a down button 67. These switches are normally biased to close their upper contacts 78, 74, as shown in FIGURE 11. There is a normally closed down limit switch 70 and a normally closed up limit switch 71 as shown in the circuit diagram of FIGURE 11. The physical position of switches 70, 71 is shown in FIGURES 1 and 9. Switches 70, 71 are actuated under pressure from the roller 58 as shown in FIGURES 9 and 10. The switches 70, 71 are conveniently fastened 'beneath the outward flanges 43 of the channel 39.

FIGURE 11 shows the position of the electrical switches with the seat in its down position. Accordingly, down limit switch 70 is open and up limit switch 71 is closed when the seat is down all the way. When it is desired to actuate the motor 28 to lift the seat, the up button 66 is pressed to complete a circuit from a power source 72 to the motor 28. The circuit to the motor field coil 73 is completed through the closed limit switch 71, the lower contacts 75 of the up button, the motor armature 76 and the upper contacts 74 of down button 67. When the seat reaches its uppermost position, the up limit switch 71 will open under pressure of roller 62 to open the circuit to the motor. Meanwhile, down limit switch 70 has closed under its normal bias. When down button 67 is pressed it will complete a circuit through closed down limit switch 70, lower contacts 77 of button 67, armature winding 76, and the upper contacts 78 of up button 66. The motor will run in the opposite direction and the seat will now descend until it reaches its lower-most position when down limit switch 70 will open to de-energize the motor. Meanwhile, up limit switch 71 closes under its normal bias to condition the motor to again reverse direction when the up button 66 is actuated. The motor will reverse under appropriate signal from the buttons 66, 67 at any intermediate point in the range of seat movement.

As best shown in FIGURES 6 and 7, the elevator seat unit has a very low profile when closed. In a practical embodiment of the invention, the entire unit when closed is only 2% inches high. Accordingly, it is adapted to replace the seat cushion of a chair or to be interposed I between the chair bottom 80 and the seat cushion 81 of the chair, as shown in FIGURE 4. This means that the seat cushion will be disposed at a slightly higher level than formerly, but this is not regarded as a disadvantage to invalids.

Moreover, I optionally provide an elasticized fabric cover 82 which may be fitted to the unit as shown in FIGURE 3. The elasticized fabric cover 82 is in the form of a tube provided at its respective ends with drawstrings or stretch cords 83, 84 which will hold the cover snugly around the sides of the unit to conceal the lift mechanism.

The seat cushion 81 may then be attached to the seat panel 21 of the unit as shown in FIGURE 3. Seat cushion 81 is shown in this figure as having a cover 85 with an apron 86 with a drawstring or stretch cord 87 by which the cushion can be snugly attached to the top of the seat panel 21. The seat cushion 81 can either be the same cushion formerly used on the chair bottom 80 or an entirely different seat cushion. In the latter event, it can be thinner than the original cushion if no change in ultimate level of the cushion top is wanted.

The seat unit can be operated throughout its range of movement and the elasticized fabric cover 82 will expand and retract to accommodate for movement of the seat panel 21 and will conceal in all positions the linkage mechanism within the unit and will not Wrinkle or bunch up even with the unit in its lowermost position.

As shown in FIGURES 12, 13 and 14, the elevator seat unit may be provided with a chair 90 which is especially adapted to receive the unit. In this instance, the chair bottom consists of a cross slot 91 0nd a front cross bar 92. The chair has a back 93 which may be pivotally mounted on pins 94 mounted on chair frame members 95. The bottom of the back 93 is provided with a bracket 96 having a forked connection with a stem 98 having a crank arm 97 and a threaded portion threaded into a fixed block 99 mounted on the chair bottom. Accordingly, the chair back 93 can be adjusted in its vertical inclination by rotating the crank 97.

A conventional seat cushion 102 for the chair is illustrated in FIGURE 12 and is provided with front and rear rails 103, 104. Rail 104 rests on the cross bar 91. The cushion 102 is further provided withslide rails 105. The side rails 105 rest near the front of the cushion on the cross bar 92. Rear cross rail 91 on the chair is desirably provided with a positioning stop bar 106 behind which the rear rail 104 on the cushion seats to hold the cushion in place.

The corners of the seat cushion 102 are further provided with gusset blocks 107 and with corner blocks 108. The gusset plates 107 and corner blocks 108 do not have any particular function in the use of the chair as shown in FIGURE 12, other than to reinforce the seat frame corners. However, they form a socket into which the seat panel 21 of the elevator seat unit fits, as shown in FIGURES 13 and 14. For this purpose front rail 92 is provided with a notched edge or rabbit 111 which, together with the stop bar 106 on rear rail 91, defines a socket to receive the base panel 20 of the elevator seat unit. As shown in FIGURE 14, the notch 111 and stop bar 106 confine the base plate 20 both laterally and horizontally.

The seat cushion 102 can simply be placed on top of the seat panel 21 of the elevator seat unit, the corners of which will be received against portions of the corner gusset plates 107 and laterally against the corner blocks 108, as shown in FIGURE 14, thus to socket or telescope the seat cushion 102 onto the seat panel 21. As is clearly apparent from comparing FIGURES 12 and 13, the interposition of the elevator seat unit between the cushion and the chair bottom adds very little to the overall height of the seat cushion and the chair has equal utility either with or without the elevator unit installed therein.

From the foregoing it is clear that the elevator seat unit of the present invention can neither be incorporated in a chair frame designed especially to receive it, as shown in FIGURES 12-14, or it can be used on any chair as shown in FIGURES 2, 3 and 4. The flatness of the upper surface of the seat panel 21 and the lower surface of the base panel, as well as the thinness of the unit when closed, as shown in FIGURE 7, is particularly advantageous when the unit is to substitute for a conventional seat cushion or to be interposed between such a cushion and a chair bottom. Accordingly, the unit is readily removable from the chair so that the chair may be used with or without the unit, and the unit is readily shifted from one chair to another.

The electric plug 72 for the unit can simply be inserted into any handy electrical socket and the motor controlled by the control box 65. While the invention has been described as it is applied to a chair, it is clear that it may be incorporated in any seating unit.

I claim:

1. In a chair having a seat bottom, a seat and a power operated seat elevator unit by which the seat is both raised and tilted forwardly to assist a person rising from the chair, the improvement by which the seat elevator unit is readily removable from the chair so that the chair may be used with or without the unit and the unit is readily shifted from one chair to another, said improvement comprising the structure of the seat elevator unit in which the unit is made compact with a low thin profile and comprises a base panel, a seat panel and elevator mechanism between said panels including a motor for raising said seat panel with respect to the base panel, said panels having substantially fiat outer surfaces which are close together when the seat panel is in lowermost position, means removably positioning the base panel on the seat bottom, linkages between said base and seat panel, means coupling the motor to the linkages to move the linkages between an upwardly projecting position to raise the seat and to move the linkages to a lowermost position in which the seat is lowered and in which said linkages are all horizontal and between said base and seat panels, thus to occupy a minimum vertical dimension, whereby said unit has a low profile when the seat unit is in said lowermost position, said linkages comprising a non-parallelogram linkage system to tilt the scat panel forwardly in the course of elevating it.

2. The device of claim 1 in which said linkages comprise a link connecting said seat panel to said base panel, said means coupling the motor to the linkages comprising a cam in support relation to said seat panel, a cam 1ift ing carriage mounted on said base panel and motion transmitting connecting means from said motor to said carriage.

3. The device of claim 2 in which said base panel is provided with rectilinear tracks for said carriage, said motion transmitting connecting means comprising a screw having a fixed axis of rotation, a threaded connection of the screw to the carriage whereby rotation of the screw drives the carriage along its rectilinear tracks and a rotary connection of the screw to the motor.

4. The device of claim 2 in combination with means for adjusting the effective length of said link.

5. The device of claim 2 in which said cam has a cam lifting carriage bearing surface curved on an are which changes its angle of incidence with the carriage as the carriage moves therealong for uniform transmission of lifting force from the motor to the seat panel.

6. The device of claim 5 in which said cam comprises another link connecting the seat panel and the base panel.

7. The device of claim 1 in further combination with an elastic fabric about the sides of said unit to enclose the space between said seat and base panels.

8. The device of claim 1 in which the seat bottom of the chair has mounting means for alternatively receiving said seat elevator unit and a seat cushion.

9. The device of claim 8 in which the seat bottom of said chair is provided with socket forming means to receive said seat elevator unit.

10. The device of claim 8 in which said seat cushion is provided with socket forming means into which said seat elevator unit fits.

11. The device of claim 1 in combination with motor control mechanism including an up button, a down button and circuit means responsive to said buttons for running the motor in one direction or the other in response to manipulation of said buttons.

12. The device of claim 11 in which said circuit means comprises limit switches responive to the respective extreme positions of the seat panel to de-energize the motor.

References Cited by the Examiner UNITED STATES PATENTS 213,512 3/ 1879 Landis 297-338 581,486 4/1897 Monkiewicz 108-145 974,769 11/ 1910 Hoff 248-376 1,178,214 4/1916 Clark 297-338 1,698,344 1/ 1929 Mott 297-339 2,292,618 8/ 1942 Davis 297-338 2,540,206 2/1951 Levitin 297-345 2,596,760 5/1952 Bryant 297-361 2,928,558 3/1960 Bamford et a1. 214-1 3,023,048 2/1962 Barton 297-339 3,046,055 7/ 1962 Martens 297-361 3,091,426 5/ 1963 Bogart 248-393 FOREIGN PATENTS 530,315 12/ 1940 Great Britain. 766,163 1/ 1957 Great Britain.

C. A. NUNBERG, Primary Examiner.

FRANK B. SHERRY, Examiner.

F. K. ZUGEL, Assistant Examiner. 

1. IN A CHAIR HAVING A SEAT BOTTOM, A SEAT AND A POWER OPERATED SEAT ELEVATOR UNIT BY WHICH THE SEAT AND A POWRAISED AND TILTED FORWARDLY TO ASSIST A PERSON RISING FROM THE CHAIR, THE IMPROVEMENT BY WHICH THE SEAT ELEVATOR UNIT IS READILY REMOVABLE FROM THE CHAIR SO THAT THE CHAIR MAY BE USED WITH OR WITHOUT THE UNIT AND THE UNIT IS READILY SHIFTED FROM ONE CHAIR TO ANOTHER, SAID IMPROVEMENT COMPRISING THE STRUCTURE OF THE SEAT ELEVATOR UNIT IN WHICH THE UNIT IS MADE COMPACT WITH A LOW THIN PROFILE AND COMPRISES A BASE PANEL, A SEAT PANEL AND ELEVATOR MECHANISM BETWEEN SAID PANELS INCLUDING A MOTOR FOR RAISING SAID SEAT PANEL WITH RESPECT TO THE BASE PANEL, SAID PANELS HAVING SUBSTANTIALLY FLAT OUTER SURFACES WHICH ARE CLOSE TOGETHER WHEN THE SEAT PANEL IS IN LOWERMOST POSITION, MEANS REMOVABLY POSITIONING THE BASE PANEL ON THE SEAT BOTTOM, LINKAGES BETWEEN SAID BASE AND SEAT PANEL, MEANS COUPLING THE MOTOR TO THE LINKAGES TO MOVE THE LINKAGES BETWEEN AN UPWARDLY PROJECTING POSITION TO RAISE THE SEAT AND TO MOVE THE LINKAGES TO A LOWERMOST POSITION IN WHICH THE SEAT IS LOWERED AND IN WHICH SAID LINKAGES ARE ALL HORIZONTAL AND BETWEEN SAID BASE AND SEAT PANELS, THUS TO OCCUPY A MINIMUM VERTICAL DIMENSION, WHEREBY SAID UNIT HAS A LOW PROFILE WHEN THE SEAT UNIT IS IN SAID LOWERMOST POSITION, SAID LINKAGES COMPRISING A NON-PARALLELOGRAM LINKAGE SYSTEM TO TILT THE SEAT PANEL FORWARDLY IN THE COURSE OF ELEVATING IT. 